iisCCiisCC and iisCARTcc support real-time clearing with the aforementioned processors. It will also support authorization of charges if your merchant account does not support real-time clearing.
The component also handles credit card validation so that the network does not need to be contacted to validate the card number and expiry date. It can also be placed into test mode where it will act simply as a validator as you build your site.
iisCC and iisCARTcc have a system which prevents duplicate charges being run by multiple submissions, full logging to track problems, and is extremely easy to use.